Carbon arc lamp



S. NICKELSBURG CARBON ARG LAMP S'Sheets-Sheet 1 Filed March 19, 1940 Jan. 26, 1943.

INVENTOR SIOA/EV N/C/(ESUG @BY J ATTORNEY III) Jan. 26, 1943. s. NICKELSBURG CARBON ARG LAMP Filed March 19, 1940 3 sheets-Sheet 2 INVEN-roR ,wc/(53096 SIDA/E Y @Y Jan. 26, 1943. s! NICKELSYBURG CARBON ARCv LAMP Filed March 19, 1940 3 Sheets-Sheet 3 INVENTOR slp/VFY /V/CKELSB RG ATTRNEYv Patented Jan. 26, 1943 UNITED CARBON ARC LAMP Sidney Nickelsburg, New York, N. Y., assigner to Morelight Company, Inc., New York, N. Y.

Application March 19, 1940, Serial No. 324,767

(Cl. E14-53) 12 Claims.

The present invention relates to a method and apparatus for producing an electric arc for use in motion picture projections, search lights, etc., and deals with reflector arc lamps and with stereopticon attachments therefor.

The improvements contemplated in this invention are manifold, all seeking to provide apparatus having increased efficiency both in improved performance and in reduced cost of operation.

The carbon feed for lamps of the indicated character, has been a cause of faulty and imperfect operation. Heretofore, arc lamps of the indicated character were provided with carbon feed mechanism which fed the negative and positive carbons at a nearly xed ratio. The speed of the feed could be increased or decreased but the ratio of feed of the two carbons could be varied only within small limits. It was not possible, therefore, to use a different trim of carbons than that for which the particular lamp was designed. To overcome this difficulty the present invention contemplates the provision of means whereby the rate of feed of each carbon may be changed independently of the other at any time during the operation of the lamp to accurately correspond with the rate of consumption of each carbon. More specifically, the invention resides in the provision of improved mechanical means incorporating variable intermittent drive mechanism for attaining the aforesaid variations in the rate of feed of each of the carbons.

This invention also contemplates the provision of improved mechanism for manually moving and positioning the carbon while under control of the feeding mechanism. The improved construction and design of the carbon transporting mechanism resulting in a smooth operation without friction grind and capable of being manipulated from the outside of the lamp house, also forms a material part of this disclosure.

Another feature of the invention resides in the improved carbon feed mechanism as above set forth in which the manual control knobs or handles, disposed outside the lamp h-ouse, remain stationary during the automatic operation of the apparatus, this mechanism and also the manual carbon-moving mechanism being selflocking in their set positions.

The advantages and desirability of the improved carbon feed and carbon-moving mech-anism as herein contemplated, may be better realized when it is pointed out that unlimited selection of the types and sizes of carbons is possible inasmuch as the rate of feed for each carbon may be varied independently of each other from little or no movement to the maximum speed required for fast burning carbons. With the herein contemplated improved mechanism, of variation is possible, i. e., from maximum speed down to zero speed.

Carbon speed indicators are represented by two knobs at the ends of two shafts, the turning of which accelerates or slows down the traveling speed of each carbon. This is done individually and manually and without interfering with each other and without any interference with the motor. These knob regulators for the intermittents for varying the ratio of speed of relative feed between positive and negative, when used in conjunction with speed-changing means of the motor drive-as by the rheostat, allows for extremely wide latitude of variation-for instance, if positive and negative are consumed at a ratio of 5 to 1, then in order to prevent breaking er freezing of the arc the motor may be speeded up or slowed down to a feed to match the rate of consumption of the carbons while maintaining the ratio of relative feed.

The foregoing objects, features, and advantages will become more clearly evident as the following detailed specification progresses. The accompanying drawings, forming the basis for the specification, illustrate the various features of the invention in exemplary form.

In the drawings- Fig. 1 is a plan view of the base of a lamphouse illustrating the novel form of carbon feeding and control mechanism.

Fig. 2 is an elevational view of the carbon feed regulating means as seen from the left of Fig. 1`

Fig. 3 is a side elevational View of the carbon feed control knobs and their associated index means.

Fig. 4 is a vertical sectional view as taken along the line 4-4 of Fig. 2.

Fig. 5 is a vertical sectional view through the center of the mechanism shown in Fig.v4.

Fig. 6 is a transverse sectional View as taken along the line 6--6 of Fig. 1.

Fig. 7 is a similar view as taken along line 1--1 of Fig. 1.

Fig. 8 is a vertical sectional View as taken along the line 8-8 of Fig. 1.

Fig. 9 is an enlarged side elevational view, partly in cross section and partly broken, showing the drive and regulating means for the negative carbon.

Fig. 10 is a view similar to Fig. 4, showing the parts arranged for continuous drive of the negative carbon regulating means.

Fig. l1 is a detail perspective view of one of the cam shoe levers utilized in the assembly of Figs. 9 and l0.

Fig. 12 is a cross-sectional view as taken on the line |2|2 of Fig. 9, showing one position of the cam shoe levers whereby continuous drive is obtained.

Fig. 13 is a view similar to Fig. l2, showing another arrangement of the cam shoe levers whereby partial feed is obtained.

Fig. 14 is a view similar to Figs. l2 and 13, but showing still another arrangement of the cam shoe levers whereby even less feed is obtained.

In that embodiment of the invention which is illustrated in the drawings, the contemplated mechanisms generally comprise a positive carbon feeding mechanism 2B; a negative carbon feeding mechanism 2 I; means for regulating the rate of feed of said mechanisms comprising the respective regulating means 22 and 23; the means 24 for supporting the positive carbon; the means 25 for supporting the negative carbon.

Carbon ,feeding mechanism Positive carbon-This mechanism 23 comprises essentially the fixed brackets and 3| between which are supported in parallel relation guide means such as the rods 32. Upon the guide rods 32 there is mounted for movement therealong a carriage such as 33 and upon said carriage and upon the fixed vertical shaft 34 thereof, there is preferably rotatably mounted a wormwheel 35 and a chain sprocket 36 keyed thereto. allel relation to the guide rods 32 and having meshing engagement with the wormvvheel 35, there is arranged a driven screw worm 31. The sprocket 36 is engaged by one run of a chain 38 trained around the sprockets 39 and 4U. These two sprockets are arranged for free rotation upon vertical shafts and upon the sprocket 4i) there is xedly carried a wormwheel 4| having engagement with a worm 42 formed with an extension shaft 43 and terminating in a manipulating knob 44 accessible from the outside of the lamphouse. The carriage 33 may be provided with a positive carbon supporting bracket 45 and the bracket 33 may be extended to provide a positive carbon steadying means 45 which will be later more fully described. The screw worm 31 is formed with a rearward extension 41 driven in a manner later described.

It may be seen that upon rotation of the shaft 41 and thus of the screw worm 31, rotation is imparted to the worm wheel and sprocket 35-38, the sprocket 3S, in this manner, moving along the chain 38 engaged thereby to cause a traversing of the carriage 33 along the guide rods 32. The rate of movement of this carriage is determined by the speed of the shaft 41. At any time during the movement of the carriage, its position may be advanced or retracted by manipulation of the control knob 44 to advance or retract the chain from its previously set position. This manual adjustment can, of course, also be made when the carbon feed is not in operation. It will be noted that the position of the chain 33 is maintained in any set position because of the selflocking properties of the wormwheel and worm 4| and 42. It is evident, then, that the positive carbon 48 may be arranged to be fed at a desired rate of speed as imparted by the rotation of the shaft 41 and that correction of the feed is available at any time through the medium of the knob In par- 44, the sprocket chain 38 through its association with the sprocket 3B, causing the carriage 45 to traverse the worm screw 31.

Negative carbon-This mechanism generally designated 2|, comprises the brackets 50 and 5|, between which are positioned the guide rods 52. Upon these rods there is guided for traverse the carriage 53, upon which is mounted the vertical stub shaft 54. On this shaft are carried the freely rotatable sprockets and 55 which are connected and rotate as a unit. The former, preferably smaller, sprocket is arranged to engage one run of a chain 51 trained around the sprockets 5S and 59, said sprocket 58 being supported on a vertical shaft fixed on the bracket 50 and the sprocket 59 similarly supported on the bracket 5|. Upon the shaft 5B, there is also mounted a worm wheel 6| secured with the sprocket 58, and the worm wheel 6| is engaged by a worm 62 controlled by a shaft 63 terminating in a manual knob 64 accessible from the outside of the lamphouse.

The brackets 50 and 5| are each preferably provided with fixed vertical shafts upon which are rotatably mounted the respective sprockets 65 and 66 around which is trained a chain 61 having one run thereof in engagement with the sprocket 56 on the carriage 53. On the shaft supporting the sprocket 65, there is also mounted a. wormwheel 58 keyed to the sprocket 65 and arranged to be driven in a manner hereinafter described.

The rotation imparted to the worm wheel 68 is transmitted to the chain 61 to cause rotation of the sprocket 5G and thus traversing movementl of the carriage 53 along its guide rods 52, because of the engagement between the sprocket 55 and the chain 51. rhe speed of rotation of the worm wheel 68 determines the rate of feed of the negative carbon 59 carried by the carriage 53. Should adjustment of the carbon 69 be necessary at any time during the operation of the feed mechanism, manipulation of the knob 54 to move the chain 51, may be readily had.

Carbon feed regulating means Positive carbon-This mechanism generally designated 22, is arranged to impart a desired rate of rotational speed to the shaft 41 of the carbon feeding mechanism 2U.

An electric motor 10 controlled by suitable resistor rheostats (not shown) is designed to drive, through the medium of speed reducing means 1|, a shaft 12a. Upon this shaft is provided a pinion gear 1| having meshing engagement with a gear 12 which in turn is arranged to drive a gear 13. The gear 13 is mounted upon a shaft 14 (Fig. 5) in co-aXia-l alignment with a second shaft 15 supported in a bracket 15 on the base of the lamp house. rihe shaft 15 carries a ratchet wheel 11 which is adapted to be engaged by a drive pawl 13 carried upon a spring arm 19 mounted upon the shaft 14. Also carried by the shaft 15 there is preferably provided a worm 80 having driving engagement with a wormwheel 8 I, the latter being mounted upon the shaft 41, previously described. It is evident that the drive pawl 18, carried by the driven shaft 14, will impart rotation to the shaft 41 through the medium of the ratchet wheel 11, the worm and the wormwheel 8| and that this drive will be continuous until such time as the drive pawl 18 is moved from engagement with the ratchet wheel Inasmuch as it is desired to vary the rate of speed of the shaft 41 as previously set forth, provision is made to cause disengagement of the drive between the mentioned pawl and ratchet. To this end, a pair of levers 82, commonly pivoted as at 83 to the bracket l, are each provided with an approximate semi-cylindrical cam shoe 84 disposed adjacent the ratchet ll. Each of the levers 82 is also fromed with an upreaching extension 95 in engaging relation with a cone 8S upon a manually rotatable shaft 257 provided with a control knob 88 disposed outside of the lamphouse. The levers 82 are each preferably formed with a lower extension 89 which are urged towards each other as by means of a tension spring 98.

The loss of engagement between drive pawl and the ratchet is attained by providing a roller 92 which maintains contact with the cam shoes 84 and thus when the shoes are disposed beyond the teeth of the ratchet, disengagement of the pawl v from said teeth is had.

It is evident that when the cone 89 is moved out of engagement with the upward extensions 85 of the levers 82, as by means of longitudinal movement of the shaft 8l' through the medium of the screw 9|, the spring 90 will draw the lower extensions 89 of said levers towards each other and the cam shoes 84 of said levers will be disposed within the confines of a circle drawn through the bases of the teeth of the ratchet Tl'. The drive pawl 18 will then be in continual engagement with said ratchet. Upon projecting the cone 86 between the extensions 85, the cam shoes 84 of the levers 82 will be moved outwardly around the pivot 83 so that some of the teeth of the ratchet 11 will be disposed entirely without the periphery of said shoes. Thus, as the drive pawl 'I8 rotates, these shoes will cause disengagement of the drive between said pawl and the ratchet to provide a period of rest for said ratchet and thus for the shaft 41. The degree of projection of the cone 86 to vary the spread of the upper extensions 85 of the levers determines the proportion of drive period as related to non-drive period between the pawl and the ratchet.

The cam shoes 84, at their adjacent ends, are preferably provided with overlapping extensions to obviate loss of contact of the roller 92 with said shoes at any time required.

When the proper rate of feed has been determined for the positive carbon, and set as by means of the knob 88, it is essential to know whether this setting has been disturbed, and to provide means for quickly restoring the setting to its ideal position. For this purpose, a pointer 93 (Fig. 3) is provided to be read in association with an index mark 94. This pointer, springtensioned at 95, is mounted on a stub shaft 96, having a radialy disposed arm 91, associated with a cone 99 on the shaft 8l. When the shaft 81 is manipulated to set the feed, which may be done while the lamp is in operation and without disturbing anything else, by merely turning knob 88, the cone thereon, through the medium of the arm 97, rotates the shaft 9S to place the pointer 93 in a certain position. When the speed rate is set, the screw 99 is loosened and the pointer 93 brought in alignment with the index 94. Should the operator at any time nd the pointer off this index mark in either the slow or fast direction, he can then manipulate the knob 88 to re-set the mechanism to the desired condition for rate of feed, without the necessity of again making an observation for from to 30 minutes to determine the rate of consumption of the carbons,

and of course, he will also reposition the carbon tips by manipulation of knobs 44 and 6d. l

It should be noted that the moving parts of the drive are all confined within the lamp house, only the manual knobs 88, 88a, 4d and 64 being accessible for the various settings. It will also be noted that these knobs are at rest as are the pointers 93, during the operation of the device.

Negative carbon-The mechanism for setting the rate of feed of the negative carbon, generally designated 23, is essentially similar to the mechanism above described, and the corresponding parts therefor have been given reference num,- bers similar to those previously described. The drive for this mechanism is obtained from the gear "l2, and its knob 88a is employed for setting the rate of feed of the negative carbon in exactly the same manner as the knob 88 is employed for setting the rate of feed of the positive carbon.

Positive carbon supporting means In order to steady the burning end of the positive carbon during movement of the feed carriage 45, to obviate variation in the quality of the arc, this invention contemplates utilizing the flexibility or elasticity inherent in carbons available for this use. The means for supporting the positive carbon is generally designated 24. The extension 45 of the carriage 33 is preferably provided with a carbon ,clamp |89 having an angularly disposed seat IBI so that the carbon when held in said clamp, has its burning end disposed below the point of clamping thereof, the lowest point of the seat, however, being in line with the carbon supporting surface of the crotch 49. The steadying crotch 46 which serves as a guide for the carbon at a point adjacent its burning end, is preferably adjustably positioned so that the carbon is flexed upwardly to bring said end into proper alignment with the center of the reflecting mirror used in the lamp house.

Negative carbon supporting means The negative carbon supporting means is generally designated 25.

The negative carbon 69 is also arranged to .be flexed, this carbon being held in a carbon holder ll, which is provided with an adjusting means lll for obtaining the degree of flexure desired. In practice, in order to obviate initial accurate alignment of the carbons, the negative carbon may be initially set somewhat above the positive carbon and then reset by means of the adjusting means IH to set the negative carbon into desired alignment with the positive carbon. The seat for the negative carbon may be angled in a manner similar to that described for the positive carbon to obtain flexing'. In this manner assurance is had that the arc will remain steady during the operation of the apparatus.

It should be understood, however, that this disclosure is intended as exemplary only and may be changed in design, size and proportion without departing from the spirit and scope of the invention, as outlined in the appended claims.

What I claim as new and desire to secured by Letters Patent is:

l. In a lamp of the character described, in combination, a negative carbon feeding mechanism, a positive carbon feeding mechanism, means for operating both said feeding mechanisms, and means for regulating the rate of feed of each mechanism independently, each regulating means comprising a ratchet wheel, a driving pawl cooperating therewith and driven by said operating means, means for operatively disengaging said pawl from said ratchet wheel in an intermittent manner, and manually operable means for setting said pawl disengaging means to suit the rate of consumption of each respective carbon.

2. In a lamp of the character described, a carbon feeding mechanism, means for operating said mechanism, and means for regulating the rate of feed of said mechanism comprising a ratchet wheel operatively connected with said feeding mechanism, a pawl for driving said ratchet wheel and operatively connected with said operating means, means for intermittently disengaging said pawl from said ratchet wheel, and manually operable means for setting said pawl disengaging means to suit the rate of consumption of said carbon.

3. In a lamp of the character described, a carbon carrying' device, means for advancing said device including intermittent drive means, and means for varying the rate of speed of said drive means, said intermittent drive means comprising a ratchet, a drive pawl therefor and means for disengaging said pawl from driving engagement with said ratchet, and said speed varying means including means for variably setting said pawl disengaging means.

4. In a lamp of the character described, means for advancing a carbon of said lamp inc1uding intermittent drive means, comprising a driven pawl, a ratchet wheel operably associated therewith, shoe means positioned in such relation to said ratchet wheel as to cause intermittent engagement and disengagement between said pawl and said ratchet wheel, and means for setting said shoe means for varying said intermittent engagement and disengagement from one extreme to the other.

5. In a lamp of the character described, a carbon feeding device comprising a feed screw, power means for rotating said feed screw, means for varying the effective rate of feed of said feed screw, a carbon holder, a worm wheel mounted thereon and in mesh with said feed screw, a sprocket pinion mounted for rotation with said worm wheel, a chain in mesh with said sprocket, and means for guiding said carbon holder for movement as imparted by the rotation of the sprocket along the links of said chain.

6. In a lamp of the character described, a carbon feeding device comprising a feed screw, power means for rotating said feed screw, means for varying the effective rate of feed of said feed screw, a carbon holder, a worm wheel mounted thereon and in mesh with said feed screw, asprocket pinion mounted for rotation with said worm wheel, a chain in mesh with said sprocket, means for guiding said carbon holder for movement as imparted by the rotation of the sprocket along the links of said chain, and means for imparting auxiliary movement to said carbon holder during operation thereof, said means .comprising manually operable means for moving said chain to impart auxiliary rotation of said sprocket.

7. In a lamp of the character described, a carbon feeding device comprising a feed chain, power means for moving said chain, means for varying the effective rate of feed of said chain, a carbon holder, a sprocket mounted thereon and engaged with said chain, a second sprocket mounted for rotation with the first-mentioned sprocket, a second chain engaged with said second sprocket, and means for guiding said carbon holder for movement as imparted by the rotation of said second sprocket along the links of said second chain.

8. In a lamp of the character described, a carbon feeding device comprising a feed chain, power means for moving said chain, means for varying the effective rate of movement of said chain, a carbon holder, a sprocket mounted thereon and engaged with said chain, a second sprocket mounted for rotation with the first-mentioned sprocket, a second chain engaged with said second sprocket, means for guiding said carbon holder for movement as imparted by the rotation of said second sprocket along the links of said second chain, and means for imparting auxiliary movement to said carbon holder during operation thereof, said means comprising manually operable means for moving said second chain to impart auxiliary rotation to said second sprocket.

9. In a carbon arc lamp, a carbon feeding device having means for automaticaly feeding a carbon at a uniform rate, means for causing auxiliary feed of said carbon during said automatic feed comprising a movable sprocket chain, with one run thereof parallel with the automatic feed means, gearing operatively peripherally meshing with said sprocket chain and with said automatic feed means, manual means to move the sprocket chain to rotate the gearing to cause it to traverse the automatic feed means, and means to restrain the sprocket chain against movement by any means except the said manual means.

10. In a carbon arc lamp, a carbon feeding device comprising a carbon holder, a power driven means for moving said carbon holder at a uniform rate, and a sprocket chain movably mounted adjacent to and with one run thereof parallel to the power-driven means, gearing carried by the carbon holder and in mesh with .both the powerdriven means and the sprocket chain, said sprocket chain being normally restrained against movement but being unrestrainedly manually movable to cause auxiliary movement of said carbon holder, regardless of whether the powerdriven means is moving or not.

11. In a carbon arc lamp, a carbon feeding device comprising a carbon holder, a powerdriven means for moving said carbon holder at a uniform rate, and a sprocket chain movably mounted adjacent to and with one run thereof parallel to the power-driven means, gearing carried by the carbon holder and in mesh with both the power-driven means and the sprocket chain, said sprocket chain being normally restrained against movement but being unrestrainedly manually movable through a worm and worm wheel unit to cause auxiliary movement of said ca-rbon holder, regardless of whether the powerdriven means is moving or not.

12. In an arc lamp adapted to employ a pair of electrodes, a movable holder for each electrode, gearing rotatably mounted on each electrode holder, and a feeding mechanism for each holder, said feeding mechanism comprising a pair of sprocket chains, said gearing having simultaneous meshing engagement with both sprocket chains, means to manually move one of said chains, power-driven means to move the other of said chains, and means for adjustably regulating mechanically the rate of feed of the power-driven means.

SIDNEY NICKELSBURG. 

